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Advisor(s)
Abstract(s)
Na fabricação de peças de materiais de cariz polimérico, uma das metodologias empregues para melhorar as propriedades mecânicas de uma determinada zona, consiste em criar secções retas e finas de material, denominadas de frisos, que conferem uma maior rigidez na área aplicada. Isto é muito útil quando apenas uma porção pequena da peça se encontra a condições de trabalho mais exigentes, pois funciona como uma medida de reforço geométrico, a um custo relativamente reduzido. Ora, de maneira a poder-se reduzir ainda mais os custos de produção, é do interesse das empresas, otimizar o design destas geometrias, de forma a ser gasto a menor quantidade de matéria-prima possível, enquanto se mantêm as propriedades desejadas pelo cliente. A presente dissertação tem como objetivo a otimização do design destes mesmos frisos, em certos componentes de interior de automóveis da empresa Simoldes Plásticos®. Para se alcançar este objetivo desenvolveram-se scripts em Python que permitem fazer análises sequenciais e automáticas no software Simulia Abaqus®, através de simulações pelo Método de Elementos Finitos (MEF), onde as respetivas peças, com diferentes geometrias de reforço, foram submetidas a um ensaio de flexão, e os dados das respostas dos sistemas foram processados automaticamente, de maneira a determinar-se a combinação de características que melhor se adequa ao componente. Para o desenvolvimento do programa, as peças foram primeiro modeladas no software de CAD Cátia V5®, tendo-se depois recorrido à simplificação das mesmas, através da supressão de atributos irrelevantes para a simulação, e a implementação de superfícies médias. As peças simplificadas foram depois transferidas para o Simulia Abaqus® onde se fez uma simulação, sem que tenham sido aplicados frisos, de maneira a utilizar o código resultante, como base para a construção do modelo do script final. Com a base do programa feita, procedeu-se com a formulação do algoritmo responsável pelo desenho, e parametrização automática dos frisos, bem como as funções relativas ao pré-processamento, pós-processamento, desenvolvimento de um Graphical User Interface (GUI), envio de relatórios por correio eletrónico e alteração das prioridades dos programas presentes no sistema operativo. Com o software desenvolvido, correram-se as simulações, tendo-se obtidos os dados sobre a geometria dos frisos que permite satisfazer os requisitos do cliente, utilizandose a menor quantidade de material possível.
In the manufacturing of polymeric parts, one of the methodologies used to improve the mechanical properties of a given area is to create straight and thin sections of material, called ribs, which provide greater rigidity to the applied area. This is very useful when only a small portion of the part is under more demanding working conditions, as it works as a geometrical reinforcement measure, at a relatively low cost. However, for companies whose production focus is on this type of components, it makes sense that they want to spend as little material as possible, while giving them the properties desired by the customer. This dissertation aims to optimize the design of these same ribs, in certain car interior components from Simoldes Plásticos®. To achieve this goal, Python scripts were developed that allow automatic sequential analysis in the Abaqus® software, using the Finite Element Method (FEM). Where different combinations of material and geometric properties of the ribs were tested, and the response of the components to a bending test was observed. With the data obtained, the best possible geometry was then selected. For the development of the software, the parts were first modelled in the CAD software Catia V5, having then resorted to their geometrical simplification, through the suppression of irrelevant attributes for the simulation, and the implementation of mid-planes. The simplified parts were then taken to Abaqus® where a simulation was carried out, without ribs having been applied, in order to use the resulting code as a constructor of the part in the final script. With the constructer completed, next came the coding of the function responsible for the parameterization of the friezes geometry, as well as the functions related to post-processing, development of a Graphical User Interface (GUI), sending reports via email and changing program priorities in the operating system. With the developed software, the simulations were run over a weekend, having obtained data on the best geometry for the friezes, and implemented these in the final piece.
In the manufacturing of polymeric parts, one of the methodologies used to improve the mechanical properties of a given area is to create straight and thin sections of material, called ribs, which provide greater rigidity to the applied area. This is very useful when only a small portion of the part is under more demanding working conditions, as it works as a geometrical reinforcement measure, at a relatively low cost. However, for companies whose production focus is on this type of components, it makes sense that they want to spend as little material as possible, while giving them the properties desired by the customer. This dissertation aims to optimize the design of these same ribs, in certain car interior components from Simoldes Plásticos®. To achieve this goal, Python scripts were developed that allow automatic sequential analysis in the Abaqus® software, using the Finite Element Method (FEM). Where different combinations of material and geometric properties of the ribs were tested, and the response of the components to a bending test was observed. With the data obtained, the best possible geometry was then selected. For the development of the software, the parts were first modelled in the CAD software Catia V5, having then resorted to their geometrical simplification, through the suppression of irrelevant attributes for the simulation, and the implementation of mid-planes. The simplified parts were then taken to Abaqus® where a simulation was carried out, without ribs having been applied, in order to use the resulting code as a constructor of the part in the final script. With the constructer completed, next came the coding of the function responsible for the parameterization of the friezes geometry, as well as the functions related to post-processing, development of a Graphical User Interface (GUI), sending reports via email and changing program priorities in the operating system. With the developed software, the simulations were run over a weekend, having obtained data on the best geometry for the friezes, and implemented these in the final piece.
Description
Keywords
Materiais de Cariz polimérico Simoldes Plásticos® Scripts Python Simulia Abaqus® Simulações pelo Método de Elementos Finitos (MEF) Flexão Cátia V5® Simplificação de geometria Superfícies Médias Pré-processamento Graphical User Interface (GUI) Polymeric parts Finite Element Method (FEM) Bending Test Suppression of irrelevant attributes Mid-plane Post-processing